build: migrate clang-tidy to LLVM 16

[scarf005]

Summary

SUMMARY: Infrastructure "DDA Port: migrate clang-tidy plugin to LLVM 16"

Purpose of change

Make it easier to get custom clang-tidy plugin easier on local environment.

Describe the solution

ported following PRs:

• Upgrade clang-tidy used in CI to LLVM 16 CleverRaven/Cataclysm-DDA#65381
• Add option to build the clang-tidy checks as an executable with CMake CleverRaven/Cataclysm-DDA#56506
• Allow C++ standard includes in clang-tidy tests CleverRaven/Cataclysm-DDA#65806

all credits to: @BrettDong @jbytheway @Qrox

Describe alternatives you've considered

RIIR

Testing

confimed it was possible to use plugin built with local LLVM 16. CI may need to be adjusted a lot since i've patchworked a lot of files.

also lots of new checks are disabled as they were too time consuming and killed runners due to 6h limit. will be handled in separate PRs.

[Qrox]

You might want to also apply CleverRaven/Cataclysm-DDA#66315 and CleverRaven/Cataclysm-DDA#66538 which are follow-ups to CleverRaven/Cataclysm-DDA#65806.

[scarf005]

thank you! will try tomorrow

[olanti-p]

Some checks definitely need to be disabled. The tidy runner seems to be timing out because of the sheer amount of new warnings.

[scarf005]

temporarily disabled 'check all affected files' for now (three header changed in this PR affects entire .cpp)

[olanti-p]

It doesn't seem to work at all now.

[scarf005]

aww, fixed. do you think it'd be ok to temporarily disable checking all affected source files and only run clang-tidy on changed files?

[olanti-p]

If you mean, disable checking .cpps if they were not changed but include a header that was changed, then no, it won't work this way.

C++ compilers (and clang-tidy checks by extension) need the entire preprocessed file to work with, and preprocessed file is created from .cpp and all its #included headers + defines passed to the compiler.

If that "affected files" check was disabled, then one PR could introduce error in header file that's only apparent when analyzing together with relevant .cpp, but CI would accept that, and then some other PR that happens to (correctly) modify that .cpp in a different place would trigger the check and get yelled at for no reason.

[olanti-p]

As I've mentioned before, you should start with fixing and/or disabling the checks added in this PR. If you check the build logs, the new checks spew billions upon billions of repeating errors, so it's quite possible the build times out simply because clang spends most of the time formatting error output.

BN builds 2-3 times faster than DDA, I say it's safe to expect our tidy could also run 2-3 times faster.

[scarf005]

a few days ago i tried disabling all new checks and still stumbled across 360m limit, as point.h, make_static.h, translations.h affected entire codebase. let's try again...

ref #3113: changed file detection relies on makefile includes target, will check if this could be moved to CMake as well, preferably using LLVM tooling in the following PR.

[scarf005]

every new checks are disabled but it still hits time limit. this time limit hit is specifically caused due to changes in aforementioned 3 headers. which caused clang-tidy to run checks for every source files.

i think this PR should be merged despite that, as

• affected file tracing behavior is kept back
• it's planned to open followup PRs with running clang-tidy.

[olanti-p]

I strongly disagree.

Tidy job works fine, while this PR in its current state breaks it completely.

Running tidy locally should not be a priority over running it in CI, because nobody runs it locally except when they're working on some tidy issue, but CI runs it for all C++ changes.

There's no immediate need to upgrade to tidy + LLVM 16, this PR is not a blocker for anything, it should be a self-contained upgrade, not downgrade.

If you claim you've disabled all the new checks and still it times out, takes more than 6 hours to complete, but at the current state of things tidy works and takes less than 2 hours for the entire run on all files, where does the >3 times increase come from?

[scarf005]

keeping it draft until #2250 to reduce cognitive load